The Ducal Crypt (German: Herzogsgruft) is a burial chamber beneath the chancel of Stephansdom in Vienna, Austria. It holds 78 containers with the bodies, hearts, or viscera of 72 members of the House of Habsburg.
Before his death at age 25 in 1365, Duke Rudolf IV3 had ordered a crypt to be built for his remains in the new cathedral he commissioned, and it has sheltered those remains for almost 650 years. He also ordered a cenotaph for himself to be placed upstairs above the crypt, in front of the high altar. That symbolic tomb was later moved to the north choir and his epitaph written in secret symbols was placed on the wall of that choir.
The family of the ruling line of Austrian dukes was buried here after Rudolf IV, but after the dynasty became emperors they were buried in various cities (Vienna was not yet the settled seat of the emperor). After the Imperial Crypt at the Kapuzinerkirche opened in 1633, it became the new dynastic burial place.
Embalmers have known since the time of the Ancient Egyptians that it is necessary to remove the internal organs if the rest of the body is to be preserved. The containers with those organs were usually put in the coffin, but when the heir to the Imperial Throne, King Ferdinand IV of the Romans, died in 1654, he specified in his will that the container with his heart be placed in the Augustinerkirche, his body in the Imperial Crypt in the Kapuzinerkirche, and the urn with his viscera in the crypt at the Stephansdom. His instructions resulted in the foundation of the Herzgruft at the Augustinerkirche. His younger brother, Emperor Leopold I, pursued a tradition imitating that distribution of remains, and also enlarged the Imperial Crypt to make it large enough for additional future burials. The urns with viscera were thereafter regularly deposited in the Ducal Crypt in the Stephansdom. There are now 33 persons who are each buried in all three places.